The ROM card has a packaged construction such that a printed circuit board in which a ROM, with necessary connections, is provided has a contact provided on one side edge thereof, the contact being exposed outside so that when the ROM card is inserted into the connector, the printed circuit board of the ROM card is electrically connected to a main printed circuit board of the apparatus body.
FIG. 8 shows a conventional connector. This connector is of such a construction that as a ROM card 3 is inserted into a card insertion port 2 of a body 1, contacts 6 having a curved shape are outwardly pushed away in a manner as indicated by the arrows, while being held in friction contact with the ROM card 3, the contacts 6 being individually formed as such in respective contactor portions 5 of conductor strips 4 accommodated in the body 1, and that when the ROM card 3 is brought to a set position, the contacts 6 are brought into resilient contact with the contact of the ROM card 3.
Another type of conventional connector, which is shown in FIG. 9, is of such arrangement that in a body 1 there is provided an expansion member 7 such that if it is rotated a given angle (e.g., 90 degree) in one direction so that conductor strips 4 accommodated in the body 1 are outwardly pushed away against the elastic force thereof, the contact of the ROM card 3 is not brought into friction contact with contacts 6 of the conductor strips 5 when the ROM card 3 is inserted into a card insertion port 2; and after the ROM card 3 is brought to its set position, by rotating the expansion member 7 over the given angle in the reverse direction as shown by a virtual line in FIG. 9 the contacts 6 are reset to their original position under the elastic force of respective contactor portions 5 of the conductor strips 4, whereupon the contacts 6 are brought into resilient contact with the contact of the ROM card 3.
In the FIG. 8 connector, however, if the contacts 6 of the conductor strips 4 are allowed to are brought into firm resilient contact with the contact of the ROM card 3 to ensure steady continuity, a larger insertion force is required when the ROM card 3 is inserted, which hampers ease of insertion and, in addition, involves vigorous friction between the contact of the ROM card 3 and the contacts 6 of the conductor strips 4 upon insertion and withdrawal of the ROM card 3, so that the contact or contacts of either side or both sides are likely to be worn out, their performance quality being thus unfavorably affected. On the other hand, if the preload of contactor portions 5 of the conductor strips 4 is reduced in an attempt to prevent such quality deterioration, it is likely that the contact pressure between the respective contacts will be excessively reduced, with the result of poor continuity. In the FIG. 8 connector, therefore, in order to minimize possible quality deterioration of the contacts and to provide good continuity, not only is it necessary to properly design the preload for the contactor portions 5, but also it is necessary to construct the conductor strips 4 of a costly high-performance spring material and further to upgrade the deposit thickness of the contacts 6; all this naturally leads to increaded cost of manufacture. Another problem is that since the ROM card 3 is placed outside the connector when not in use and since it is subject to frequent insertion and withdrawal, it is very likely to contact quality deterioration even if aforesaid measures are taken.
Whilst, in the FIG. 9 connector, if the contactor portions 5 of the conductor strips 4 are outwardly pushed away by the expansion member 7, the contact of the ROM card 3, upon each insertion or withdrawal, is unlikely to rub against the contacts 6 of the conductor strips 4, and therefore it is possible to provide a larger preload for the conductor strips 4 to ensure steady continuity; thus, such quality deterioration due to contact wearing as above mentioned is inhibited. However, this connector requires, as its indispensable components, the expansion member 7 and various parts for controlling same, and this makes the arrangement complicated. Further, for each insertion or withdrawal of the ROM card 3, the expansion member 7 has to be controlled, which is very troublesome.
The foregoing is also true in the case of an IC card being used instead of the ROM card.